The release ISO images should be available on most of the [[mirrors|mirrors]]. If the ISO is not available on a certain mirror, please try another one or download it from the DragonFly master site. Each image is in the "Live CD" format, meaning that it boots into a running and fully functional DragonFly system, which can be used for testing or system recovery tasks as well as installation. Check the [hardware page](http://www.dragonflybsd.org/docs/supportedhardware/) or boot a Live CD to check for compatibility.

The GUI bootable USB image also contains the DragonFly git repo in /usr/src and the pkgsrc git repo in /usr/pkgsrc. The code can be trivially checked out using these repos and can be incrementally updated from master sites, post-install.

We offer roughly 10,000 pre-built [pkgsrc](http://www.pkgsrc.org) packages for this release. The [pkg_radd(1)](http://leaf.dragonflybsd.org/cgi/web-man?command=pkg_radd&section=ANY) utility may be used to download pre-built binary packages. The path can be overridden by setting BINPKG_BASE in `/etc/pkg_radd.conf`.

We supply a Makefile in `/usr` to track the pkgsrc tree and we supply a Git mirror of the NetBSD pkgsrc CVS repo at `git://git.dragonflybsd.org/pkgsrcv2.git`. We recommend that users use it, instead of pulling from NetBSD with CVS. Our Git mirror is updated several times a day. Type 'make' in /usr to see the available commands for performing these actions.

**Disk size warning** - Unless your hard disk is 50G or larger, we recommend doing a UFS install and not the default HAMMER install. We also recommend installing from the CD ISO, not the GUI .img, for smaller drives. A more serious installation should use HAMMER with at least 50G of disk space and can install from the GUI .img. HAMMER on smaller disk drives is possible but requires careful pruning to keep from filling the disk with file history.

**Virtual PC users** - Virtual PC does not supply serial numbers for the virtual disks. The system may need to be manually directed in the boot loader if the disk identifier changes. (Hit ? in the boot loader for a list of available volumes.)

**Qemu users** - If you see a large number of error messages on the console when booting, you may need to boot DragonFly with ACPI disabled. This can be done in the menu presented at initial boot. If that doesn't help, try placing hw.ioapic_enable=0 in /boot/loader.conf.

**Installer Crypt Options** - The installer can encrypt the root volume and the swap volume. It will not work properly for other volumes despite any additional check-boxes you might see. Installer and boot-time support works but is still a bit rough around the edges. Performance will be relatively high on multi-core machines.

* Introduced a new cpu topology aware scheduler, usched_dfly, and made it the default. This scheduler implements several weighted algorithms and will first try to schedule threads to different sockets (to make best use of on-chip caches). As the load increases threads are then scheduled to real cores, and finally will be scheduled to hyper-threads. Threads with similar load characteristics tend to get spread out more. The scheduler also implements wait/wakeup pairing detection and tries to move related threads closer together to reduce inter-socket cache coherency bandwidth and share L3 caches.

* Introduced a major pmap optimization for x86-64 which allows page table pages to be shared between UNRELATED processes (so it works for process's separately exec'd or forked), in situations where those processes are mmap()ing the same thing. This feature works extremely well for both sysv shared memory and mmap()-based shared memory. In tests with postgres and a 6GB shared memory block the prior memory consumption from forking is now gone. This page table sharing works even better than the original shm_use_phys sysctl. Also observed significantly faster X application startup.